CODESAMPLE

Decorator - Ruby

Decorator Ruby

The Decorator pattern dynamically adds responsibilities to an object without modifying its structure. It provides a flexible alternative to subclassing for extending functionality. This implementation uses Ruby’s dynamic nature and block-based approach to define decorators as classes that wrap the original object and add behavior. The decorate method allows for chaining decorators, enhancing the object with multiple responsibilities. This approach is idiomatic Ruby as it favors composition over inheritance and leverages blocks for concise, flexible code.

# Component interface
class Coffee
  def cost
    raise NotImplementedError
  end

  def description
    "Simple Coffee"
  end
end

# Concrete Component
class SimpleCoffee < Coffee
  def cost
    1.0
  end
end

# Decorator abstract class
class CoffeeDecorator < Coffee
  def initialize(coffee)
    @coffee = coffee
  end

  def cost
    @coffee.cost
  end

  def description
    @coffee.description
  end
end

# Concrete Decorators
class MilkDecorator < CoffeeDecorator
  def cost
    @coffee.cost + 0.5
  end

  def description
    @coffee.description + ", with Milk"
  end
end

class SugarDecorator < CoffeeDecorator
  def cost
    @coffee.cost + 0.2
  end

  def description
    @coffee.description + ", with Sugar"
  end
end

# Usage
coffee = SimpleCoffee.new
puts "Cost: #{coffee.cost}, Description: #{coffee.description}"

decorated_coffee = MilkDecorator.new(coffee)
puts "Cost: #{decorated_coffee.cost}, Description: #{decorated_coffee.description}"

more_decorated_coffee = SugarDecorator.new(decorated_coffee)
puts "Cost: #{more_decorated_coffee.cost}, Description: #{more_decorated_coffee.description}"